While the weak Christian churches of Europe seem to be more than willing to become dhimmis to Muslims, some of the older more pagan traditions are far less forgiving.
Imagine a raiding party of Vikings or pagan Germans:
“Germanic priestesses were feared by the Romans, as these tall women with glaring eyes, wearing flowing white gowns often wielded a knife for sacrificial offerings. Captives might have their throats cut and be bled into giant cauldrons or have their intestines opened up and the entrails thrown to the ground for prophetic readings.”
Put animal horns on your head and go wild. Not many African or Asian immigrants at these music fests.